As it is known, in the production of industrial plants there is often the need to provide lines for conveying material that is useful for the most disparate applications, including the conveyance of supply or discharge water, the conveyance of compressed air, the conveyance of liquids for cooling, the conveyance of food liquids, the conveyance of powders and granules, et cetera.
Of course, depending on the use, the materials of the pipes are the most suitable for the requirements; pipes made of plastics, galvanized steel, stainless steel and other disparate materials are typically used.
These pipes must be fixed to the structures of the plant by virtue of adapted elements, which allow to secure each pipe in one point so as to be able to restrain it.
The most widely used pipe fixing devices are divided substantially into two categories: a profile compression collar and a bracelet collar.
The compression collar is a collar formed by two perfectly identical strips, which are shaped like a circular arc along one portion and are straight at an end portion.
The pipe is rested, for example horizontally, on an upright and the two strips are coupled so as to face each other and surround, with their straight portions, the lateral part of the pipe, while the circular arc-like parts adapt to the portion of the pipe that is directed in the opposite direction with respect to the upright.
Two respective holes for the insertion of a locking bolt are provided in the outer ends of the strips, while the opposite ends of the strips have a T-shaped contour for insertion in a complementary vertical guide provided on the upright.
The pipe is secured because the pipe in practice is compressed by the circular arc-like portions toward the upright.
In the case of thin pipes, the pipe is squeezed in the portion of contact with the upright, causing an internal bulge.
This bulge in practice tends to obstruct the pipe partially; in the case of a flow of solid particles which can flow therein, such as for example granules of plastic material loaded with glass fiber, the granules strike the bulge, producing in the long term, due to an abrasive effect, a laceration of the pipe in the point of impact.
Another problem linked to this type of fixing collar is related to the fact that when it is necessary to fix a plurality of pipes close to each other in parallel, the closure bolt of the strips is positioned awkwardly.
The axis of said bold is in fact oriented parallel to the wall (in the typical case of the upright adjacent to the wall), so that when the pipes are mutually close, the fixing devices also are mutually close and there is no space between one and the other for easy front insertion of the head of a power screwdriver (or equivalently of a socket wrench).
Moreover, with a collar of this type, the alignment of the pipe occurs with difficulty, since said collar is fixed on the upright only when the pipe presses on said upright; it is therefore difficult to align the pipes correctly.
Further, the fact that securing the pipe corresponds to its fixing to the upright prevents said pipe from being moved or turned conveniently, for example to connect it to another pipe.
Some of the drawbacks observed in the use of the compression collar are overcome by the bracelet collar.
Said bracelet collar is constituted by two C-shaped strips, which oppositely surround the pipe and secure it.
A bolt for securing to said upright protrudes from the bottom of one of the strips.
Perforated flat portions are present on both ends of each strip, are arranged parallel to the wall, and are useful for the insertion of a bolt for fixing to the other strip.
In this case, the axis of the additional bolts is perpendicular to the wall.
This type of collar allows convenient access to the strip fixing bolts; they are in fact oriented at the front and therefore, in the case of side-by-side pipes, access to said bolts is not prevented by the nearby collar.
Likewise, it is possible to fix the pipes to the uprights without securing them completely, thus allowing their translational motion or rotation before their final securing.
However, with this type of collar, when it is necessary to have a plurality of pipes arranged side-by-side and parallel, said pipes are scarcely compact, since they are necessarily spaced by the width of the perforated flat portions.